The Shock Knife blade is plastic so when you get "hit" with it, there is no pain of impact just the shock that will make you jump a bit (you are shocked). However, a dull alloy blade stings like a bitch and induces plenty of fear.

Could the electricity pose problems for people that have pace makers, or something similar?

Medical Info

The Shocknife training knife has a potentiometer (Shock Adjustment Screw), which allows the user to adjust the level of shock received. Shocknife’s maximum setting produces a shock with a maximum of 7,500 volts with under 1 milliamp (.00075 AMPS). The shock is a LOCALIZED SHOCK ONLY with a gap space of only 1/8th of an inch. This is well below standard stun guns.

High voltage, in itself, is not dangerous. One can receive a 15,000-volt shock of static electricity from a doorknob on a dry day without harm. The physiological effect of electrical shock is determined by: the current, its duration, and the power source that produces the shock. The typical household current of 110 volts is dangerous because it can pump many amperes of current throughout the body INDEFINITELY. By contrast, the Shocknife produces a localized shock at a maximum of 7,500 volts and less than 1 milliamp (.00075 amps). The Shocknife’s output is well below the level established as “safe” by the federal government for approving such devices as the electrified cattle fence.

Its saids 7,500 Volts. A "light" Stun gun is 80,000 Volts for reference.